The present invention relates to an IC card incorporating components such as microcomputer chips and memory chips.
A conventional IC card of the type stated above is illustrated in FIGS. 1 to 3. As shown in these Figures, the conventional IC card has a thin shutter 2 for protecting external-element connection terminals 100 (see FIG. 1), and the shutter 2 is mounted on the frame 1 of the IC card so as to be slidable back and forth, i.e., in the direction of the arrow A shown in FIGS. 1 and 2. The frame 1 incorporates a printed board (not shown) on which semiconductor chips (also not shown) are mounted, the terminals 100 are also mounted on the printed board in the portion of front end thereof and are exposed when the shutter 2 is open. The shutter 2 has a base portion 3 and spring-mounting portions 4. Projections 3a and 4a are respectively formed on the shutter base portion 3 and the corresponding spring-mounting portions 4, and these projections 3a and 4a each extend along the side portions of the frame 1. Tensile springs 5 are disposed between the corresponding projection 4a formed on the portion 4 and a fixing pin 1a secured on the frame 1 to provide return tension for the shutter 2, so that the shutter 2 returns to a normal position, that is the closed position, shown in the figures when the IC card is not being used. The frame 1 is formed with guide grooves 7 which each receive therein the corresponding projection 3a of the base portion 3, so that the shutter 2 can be guided back and forth in the direction indicated by the arrow A. A stopper 8 for the shutter 2 is formed at one end portion of the frame 1. The IC card also has metal panels 6 provided on the upper and lower surfaces of the frame 1 to cover components such as semiconductor chips (not shown). An insulating material coats all of the metal panels 6.
When the IC card having the construction described above is used, the card is inserted into a card receptacle (not shown) of a card reader (not shown). At this time, the shutter 2 is moved backward against the tension of the springs 5 and assumes an opened condition in which the external-element connection terminal 100 of the IC card are connected to electrodes within the card reader respectively.
When the IC card is pulled out of the card receptacle, the external-element connection terminals 100 of the IC card are disconnected from the electrodes within the card reader, and the shutter 2 is moved forward by the tension of the springs 5 until it abuts against the stopper 8 and closes.
The conventional, IC card of this type is, however, not provided with means to guide the spring-mounting portions 4. Consequently, there is a risk that, during the opening or closing of the shutter 2, the rear part of the shutter 2 formed by the spring-mounting portions 4 may laterally move. In addition, although the stopper 8 is formed on the frame 1 and functions to stop the shutter 2 when it closes, the height of the stopper 8 is relatively low (e.g., about 0.2 mm) because of the specification for the overall structure of the IC card. Consequently, there is a risk that, when the shutter 2 closes, it may overshoot the stopper 8 and move forward to the outside of the frame 1. In this way, the conventional IC card fails to provide stable opening and closing action of the shutter 2.